Gabriele Cosmo
92 lines
3.5 KiB
C++
92 lines
3.5 KiB
C++
//
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// ********************************************************************
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// * DISCLAIMER *
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// * *
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// * The following disclaimer summarizes all the specific disclaimers *
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// * of contributors to this software. The specific disclaimers,which *
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// * govern, are listed with their locations in: *
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// * http://cern.ch/geant4/license *
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// * *
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// * Neither the authors of this software system, nor their employing *
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// * institutes,nor the agencies providing financial support for this *
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// * work make any representation or warranty, express or implied, *
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// * regarding this software system or assume any liability for its *
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// * use. *
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// * *
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// * This code implementation is the intellectual property of the *
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// * GEANT4 collaboration. *
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// * By copying, distributing or modifying the Program (or any work *
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// * based on the Program) you indicate your acceptance of this *
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// * statement, and all its terms. *
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// ********************************************************************
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//
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//
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// $Id: G4ClassicalRK4.hh,v 1.6 2002/11/20 17:56:35 japost Exp $
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// GEANT4 tag $Name: geant4-05-00 $
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//
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//
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// class G4ClassicalRK4
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//
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// Class description:
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//
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// Integrate the equations of the motion of a particle in a magnetic field
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// using the classical 4th Runge-Kutta method.
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// History:
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// - Created: J.Apostolakis, V.Grichine - 30.1.97
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// - Moved into G4MagErrorStepper: W.Wander <wwc@mit.edu> - 12/09/97
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#include "G4MagErrorStepper.hh"
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#include "G4ThreeVector.hh"
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class G4ClassicalRK4 : public G4MagErrorStepper
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{
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public: // with description
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G4ClassicalRK4(G4Mag_EqRhs *EqRhs, G4int numberOfVariables = 6) ;
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~G4ClassicalRK4() ;
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// A stepper that does not know about errors.
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// It is used by the MagErrorStepper stepper.
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void DumbStepper( const G4double yIn[],
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const G4double dydx[],
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G4double h,
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G4double yOut[]) ;
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// Given values for the variables y[0,..,n-1] and their derivatives
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// dydx[0,...,n-1] known at x, use the classical 4th Runge-Kutta
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// method to advance the solution over an interval h and return the
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// incremented variables as yout[0,...,n-1], which not be a distinct
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// array from y. The user supplies the routine RightHandSide(x,y,dydx),
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// which returns derivatives dydx at x. The source is routine rk4 from
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// NRC p. 712-713 .
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public: // without description
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void StepWithEst( const G4double yIn[],
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const G4double dydx[],
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G4double h,
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G4double yOut[],
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G4double& alpha2,
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G4double& beta2,
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const G4double B1[],
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G4double B2[] );
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// Could make above G4SixPoint to keep tangents too ...?
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G4int IntegratorOrder() const { return 4; }
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private:
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G4ClassicalRK4(const G4ClassicalRK4&);
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G4ClassicalRK4& operator=(const G4ClassicalRK4&);
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// Private copy constructor and assignment operator.
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private:
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// G4int fNumberOfVariables ; // is set default to 6 in constructor
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G4double *dydxm, *dydxt, *yt; // scratch space - not state
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};
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